基于液相色谱-四极杆飞行时间质谱法探究毒死蜱光降解行为

Study on photodegradation behavior of chlorpyrifos based on liquid chromatography-quadrupole time-of-flight mass spectrometry

中文关键词:  毒死蜱  光降解  液相色谱四极杆飞行时间质谱仪

英文关键词:chlorpyrifos  photodegradation  liquid chromatography-quadrupole time-of-flight mass spectrometry

中文摘要:

      目的 根据农药的光解反应原理, 建立一套毒死蜱的光降解模型, 探究其光降解速率规律, 同时对其降解产物进行物质鉴定。方法 利用液相色谱-四极杆飞行时间质谱法对毒死蜱溶液在紫外灯和氙灯照射下的降解行为进行研究, 并对其降解产物进行鉴定。结果 10 mg/L毒死蜱在紫外灯照射下降解半衰期为5.35 h, 在氙灯照射下降解半衰期为19.01 h; 毒死蜱的降解速率随温度升高不断加快, 在到达40℃以后速率不再上升, 同时毒死蜱光解速率随浓度的升高而降低。结论 毒死蜱的光降解符合一级动力学规律, 光降解速率次序为紫外灯>氙灯, 降解产物包括2-甲氧基-3,5,6-三氯吡啶、3,5,6-三氯吡啶-2-醇等。该研究可为评估毒死蜱对环境的生态毒性提供重要理论支撑。

英文摘要:

      Objective To establish a photodegradation model of chlorpyrifos based on the photolysis of pesticide, then understand the photolysis rule of chlorpyrifos, and complete the determination of the degradation products of chlorpyrifos. Methods The degradation behavior of chlorpyrifos solution irradiated by ultraviolet lamp and xenon lamp was studied by liquid chromatography-quadrupole time-of-flight mass spectrometry, and its degradation products were identified. Results The degradation half-life of 10 mg/L chlorpyrifos was 5.35 h under ultraviolet lamp irradiation and 19.01 h under xenon lamp irradiation. The degradation rate of chlorpyrifos increased with the increase of temperature, and stopped increasing after reaching 40℃, while the photolysis rate of chlorpyrifos decreased with the increase of concentration. Conclusion The photodegradation of chlorpyrifos accords with the first order dynamics, the order of photodegradation rate: Ultraviolet lamp>xenon lamp. Degradation products include 2-methoxy-3,5,6-trichloropyridine, 3,5,6,-trichloro-2-pyridinol. This study can provide important theoretical support for evaluating the ecological toxicity of chlorpyrifos to the environment.